I am having this issue too. When I check the newly generated Archive's folder, I can only see the folders BCSymbolMaps, Products, and dSYMs, whereas previous (and working) archives had those three, as well as the Info.plist and the folders SCMBlueprint and SwiftSupport. This happened to me after updating Xcode. I have tried all previously mentioned solutions (to my knowledge). Any help is welcome.

I have also tried uninstalling and reinstalling Xcode to no avail.

After three days of trying all solutions, it is back to normal. I updated the OS to Catalina 10.15.7 about when it came out, and didn't need to Archive since. I'm guessing this + updating Xcode was part of the issue. I fully uninstalled Xcode - https://stackoverflow.com/questions/31011062/how-to-completely-uninstall-xcode-and-clear-all-settings, reinstalled it, changed the /Users/<your user name>/Library/Developer/Xcode/Archives folder permissions to read, write and execute, shut down the computer (restarting will not do it) and started it up again. I also have the three bullets from TN2215 that KMT mentions. I hope this helps anyone.

I am also experiencing this issue. Did anyone find a solution to this? Edit: I followed this - https://github.com/facebook/react-native/issues/29279#issuecomment-658244428 and it solved the issue for me (it apparently is a react-native issue with respect to iOS 14)